1. Field of the Invention
The invention generally relates to magnetic nanowires. In particular, the invention provides multisegmented, multifunctional magnetic nanowires for the probing and manipulation of molecules at the cellular and subcellular level.
2. Background of the Invention
The ability to selectively probe and manipulate molecules at the cellular and subcellular level is critical in both basic research and the development of biotechnology applications. One powerful method to do this is to use small particles that interact with specific molecules or individual cells, and which respond to a magnetic field. This approach has found widespread application in cell sorting, biosensing, and studies of mechanical properties of cells using magnetic particles or beads.
For example, particles or beads having magnetic properties have previously been used in separation support systems (see U.S. Pat. Nos. 5,834,121; 5,395,688; 5,356,713; 4,774,265; and 4,554,088, incorporated by reference herein). In particular, magnetically separable support systems have been suggested for the detection of biomolecules by attaching a ligand to a magnetizable bead, attaching a detection molecule to the ligand, permitting the detection molecule to bind to a target molecule, and retrieving the resulting product by use of a magnetic field or other means.
However, a significant limitation of these magnetic carriers is that they have only a single chemical functionality per particle. Further, such magnetic beads or particles have a relatively uniform structure and therefore display relatively uniform magnetic properties.
It would be of benefit to have available magnetic entities which could be used to selectively manipulate and probe molecules at the cellular and subcellular level which contained multiple chemical functionalities per entity. Further, it would be of benefit if the multiple chemical functionalities were spatially resolved from each other. In addition, it would be of benefit if the magnetic properties of such entities could be manipulated and tailored to give the entities a variety of responses to an applied magnetic field.